CN113854952A - Vision detection method and system using universal equipment with camera shooting function - Google Patents

Abstract

The invention discloses a vision detection method and a system by utilizing universal equipment with a camera shooting function, which relate to the technical field of vision detection and comprise an image acquisition module, an image analysis module, a visual target display module and a visual target analysis module; the image analysis module is used for receiving the complete facial picture of the examinee and analyzing the complete facial picture by combining with the focal length information of the camera, and then calculating the size of the corresponding vision detection sighting mark in real time according to the vision recording level to be tested, so that the examinee does not need to pay attention to the object distance, the accurate size of the vision detection sighting mark is displayed, the labor is saved, and the intelligent degree of vision detection is improved; the visual target display module is used for displaying visual targets with corresponding sizes on a display screen of the general equipment; the visual target analysis module is used for analyzing according to the visual target direction selected by the examinee to determine the current vision of the examinee; the detection method is simple and effective, and can be operated only by the examinee himself, so that medical resources are saved, and social benefits are improved.

Description

Vision detection method and system using universal equipment with camera shooting function

Technical Field

The invention relates to the technical field of vision detection, in particular to a vision detection method and system by utilizing universal equipment with a camera shooting function.

Background

With the coming of the information-based era, eye protection is more and more emphasized. The most basic method for judging whether the person has myopia or other ophthalmic diseases is to detect the naked eye vision or the glasses-wearing vision of the person to be detected in a hospital in the market and then judge whether the vision of the person to be detected has problems. In general, vision examination can be performed only by using a special medical visual acuity chart in a medical institution, and ordinary people cannot judge the accuracy of own vision at any time by a convenient method in daily life. Because of the shortage of Chinese medical resources, if the vision detection can be carried out only in medical institutions, the patients can see the doctor after the symptoms of the patients are serious, and the patients can miss the optimal treatment time and get the myopia.

Disclosure of Invention

In order to solve the problems of the scheme, the invention provides a vision detection method and a system by utilizing a general-purpose device with a camera shooting function.

The purpose of the invention can be realized by the following technical scheme:

a vision detection system using universal equipment with a camera shooting function comprises an image acquisition module, an image analysis module, a visual target display module and a visual target analysis module;

the image acquisition module is used for shooting a complete facial picture of a detected person through the front camera and sending the shot complete facial picture of the detected person to the image analysis module;

the image analysis module is used for receiving a complete facial picture of a detected person, analyzing the complete facial picture by combining with the focal length information of the camera, calculating the object distance D between the person and the lens at present, and then calculating the corresponding vision detection index size in real time according to the vision recording level to be tested;

the visual target display module is used for displaying visual targets with corresponding sizes on a display screen of the universal equipment according to the sizes of the visual detection visual targets obtained by the image analysis module;

the visual target analysis module is used for analyzing according to the visual target direction selected by the examinee to determine the current vision of the examinee.

Further, the specific analysis steps of the image analysis module are as follows:

s1: carrying out face detection on a received complete facial picture of a detected person by using a face detector, identifying the outline of five sense organs, intercepting a corresponding face area, and determining the positions of pupils of two eyes;

s2: acquiring the interpupillary distance width of a detected person according to the positions of pupils of two eyes;

s3: the focal length information of the camera is obtained to be F, the object distance of the current distance lens between a person and the person can be calculated according to a similar triangle method, and the specific calculation mode is as follows: d ═ W × F)/P, where: d is the object distance between the person and the lens, W is the pupil distance width of the person to be examined, and P is the picture pixel width of the camera;

s4: calculating the size of a corresponding vision detection sighting mark in real time according to the vision recording level to be tested, wherein the specific calculation method comprises the following steps:

marking an angle formed by two points on the sighting target at the eye node N as alpha, wherein the alpha corresponds to the object distance D between a person and the lens; the side length E of the sighting target is calculated according to the following formula: e ═ optotype constant × 250 × α × p; the visual target constant corresponds to the vision record level to be tested, and each vision record level has a corresponding visual target constant; p is the constant radian coefficient.

Further, the specific analysis steps of the sighting target analysis module are as follows:

after the examinee detects a line of sighting marks, the direction of the sighting marks which are seen is selected through a direction key displayed on the display screen; judging whether the selection direction is correct or not;

if the direction is selected to be correct three times continuously, the visual target is switched to a smaller visual target, and the correct switching times are increased by one; if the selected direction is continuously wrong for three times, switching the sighting target to a larger sighting target; at this time, the number of times of error switching is increased by one; and when the correct switching and the wrong switching are respectively accumulated for three times, judging that the examinee reaches the eyesight limit at the moment, and taking the sighting target at the latest correct switching as the current eyesight of the examinee.

The vision detection system comprises a vision detection system, a front-end judgment module and a front-end judgment module, wherein the vision detection system is connected with an AP I of an operating system of the general equipment when being opened on the general equipment, and the front-end judgment module is used for detecting whether the general equipment has a front-end camera or not; if the front camera is arranged, the vision detection system can be normally used on the current general equipment, otherwise, the vision detection system cannot be used.

The system further comprises an information acquisition module, wherein the information acquisition module is used for acquiring the camera focal length information of the current universal equipment from a built-in hardware database and transmitting the camera focal length information to the image analysis module.

The vision test system further comprises an information input module, wherein the information input module is used for inputting the vision record level needing to be tested by the examinee and uploading the vision record level to the image analysis module.

Further, a vision testing method using a general-purpose device with a camera function, which is applied to a vision testing system, comprises the following steps:

v1: when the vision detection system is opened on the universal equipment, detecting whether the current universal equipment has a front camera or not through an API (application program interface) of an operating system of the universal equipment;

v2: if the front camera exists, acquiring the focal length information of the current camera through a built-in hardware database, and then inputting the vision record level to be tested through an information input module;

v3: shooting a complete facial picture of a detected person through a front camera, analyzing by combining focal length information of the camera, calculating the object distance D between a person and a lens at present, and then calculating the size of a corresponding vision detection sighting mark in real time according to a vision recording level to be tested; wherein, the detection of the size of the sighting target comprises the detection of the side length E of the sighting target;

v4: displaying the corresponding size of the sighting target on a display screen of the universal equipment according to the side length E of the detected sighting target, and selecting the direction of the sighting target viewed through a direction key on the display screen after the examinee detects one line of sighting target; and analyzing according to the visual target direction selected by the examinee to determine the current vision of the examinee.

Further, the current eyesight of the examinee is determined by analyzing according to the direction of the optotype selected by the examinee, and the specific analysis steps are as follows:

if the direction is selected to be correct three times continuously, the visual target is switched to a smaller visual target, and the correct switching times are increased by one; if the selected direction is continuously wrong for three times, switching the sighting target to a larger sighting target; at this time, the number of times of error switching is increased by one;

and when the correct switching and the wrong switching are respectively accumulated for three times, judging that the examinee reaches the eyesight limit at the moment, and taking the sighting target at the latest correct switching as the current eyesight of the examinee.

Compared with the prior art, the invention has the beneficial effects that:

the invention calculates the object distance D between the person and the lens in real time through the computer image technology, and calculates the corresponding visual inspection sighting mark size in real time according to the object distance D and the vision recording level to be tested, so that the examinee can not see the sighting mark clearly due to the change of the distance caused by the operation behavior, the visual inspection accuracy is not influenced, the examinee does not need to pay attention to the object distance, the accurate visual inspection sighting mark size is displayed, the labor is saved, and the intelligent degree of the visual inspection is improved; and then, the current vision of the examinee is determined by analyzing according to the selected sighting target direction of the examinee, the detection method is simple and effective, the operation can be completed only by the examinee, the labor is saved, the efficiency is improved, the detection can be carried out through a network, the site operation of a medical institution is not required, the medical resource is saved, and the social benefit is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a block diagram of the system of the present invention.

FIG. 2 is a flow chart of the method of the present invention.

Fig. 3 is a schematic view of the viewing angle of the subject during the inspection of the viewing object.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The traditional vision test needs to go to the medical institution for testing mainly for the following reasons: the judgment of the detection distance in the detection process of the vision detection is very accurate, detection visual charts with different sizes are required to be selected for different detection distances, and when the vision condition of a detected person is special, the real vision state can be obtained through calculation and conversion; the vision detection is that the examinee cannot independently complete the detection because of the detection distance relationship;

the invention utilizes the universal equipment with a camera, such as a computer and a mobile phone, and enables a single person to finish vision detection by a computer image identification method, can judge the vision condition of the person at any time without the assistance of a third party, and can know the vision condition of the person without going to a professional medical institution for vision detection, thereby finding the vision problem in time, seeking medical advice as soon as possible, avoiding aggravation of myopia diseases and improving vision safety;

as shown in fig. 1, a vision testing system using a general device with a camera function, which is applied to a general device with a camera function, such as a mobile phone, a computer, etc., includes a pre-determination module, an information acquisition module, an information input module, an image acquisition module, an image analysis module, a visual target display module, and a visual target analysis module;

when the vision detection system is opened on the universal equipment, the front judgment module is connected with an AP I of an operating system of the universal equipment and is used for detecting whether the current universal equipment has a front camera or not, if the front camera exists, the vision detection system can be normally used on the current universal equipment, and otherwise, the vision detection system cannot be used;

after the judgment of the front-end judgment module is passed, the information acquisition module acquires the camera focal length information of the current universal equipment through a hardware database built in the universal equipment and uploads the camera focal length information to the image analysis module;

the information input module is used for inputting the vision recording level to be tested to the image analysis module by the examinee; the image acquisition module is used for shooting a complete facial picture of the examinee through the front camera and sending the shot complete facial picture of the examinee to the image analysis module;

the image analysis module is used for receiving a complete facial picture of the detected person, analyzing the picture by combining with the focal length information of the camera and calculating to obtain the size of the visual target for vision detection; the specific analysis steps are as follows:

s1: carrying out face detection on the received complete face picture of the detected person by using a face detector, identifying the outline of five sense organs, particularly the positions of pupils of two eyes, intercepting the corresponding face area,

s2: acquiring the interpupillary distance width of a detected person according to the positions of pupils of two eyes; wherein the interpupillary distance of the adult male is 60-73 mm, the interpupillary distance of the adult female is 53-68 mm, and the system can calculate the approximate value of the interpupillary distance of the examined person according to the gender and the built-in database;

s3: the method comprises the following steps of obtaining the focal length information of a camera, and calculating the accurate distance from a person to a lens at present according to a similar triangle method, wherein the specific calculation mode is as follows: d ═ W × F)/P, where: d is the object distance between the person and the lens, W is the pupillary distance width of the person to be examined, F is the focal length of the camera, and P is the picture pixel width of the camera;

s4: calculating the size of a corresponding vision detection sighting mark in real time according to the vision recording level to be tested, wherein the specific calculation method comprises the following steps:

as shown in the view angle diagram of fig. 3, an angle formed by two points on the visual target at the eye node (N) is expressed by α, and the unit is divided, and α corresponds to an object distance D from the person to the lens; the visual angle range of the visual target 3.7-5.1 is 19.953 '-0.794', and the corresponding radian coefficient constant is p;

the side length E of the sighting target is calculated according to the formula: e ═ optotype constant × 250 × α × p; the visual target constant corresponds to the vision record level to be tested, and each vision record level has a corresponding visual target constant;

according to the method, when the object distance D of the subject changes, the corresponding alpha also changes, and if the other parameters are not changed, the side length E of the sighting target also changes, so that the size of the sighting target can be adjusted according to the object distance D of the subject; the accurate size of the visual inspection sighting mark is displayed under the condition that the examinee does not need to pay attention to the inspection distance, so that the labor is saved, and the intelligent degree of visual inspection is improved;

the image analysis module is connected with the sighting target display module, and the sighting target display module is used for displaying sighting targets with corresponding sizes on a display screen of the universal equipment according to the size of the vision detection sighting target obtained by the image analysis module, wherein the sighting targets are arranged in a line on the display screen;

the visual target analysis module is used for analyzing according to the visual target direction selected by the examinee to determine the current vision of the examinee, and the specific analysis steps are as follows:

after the examinee detects a line of sighting marks, the direction of the sighting marks which are seen is selected through a direction key displayed on the display screen;

judging whether the selection direction is correct or not; if the direction is selected to be correct three times continuously, the visual target is switched to a smaller visual target, and the correct switching times are increased by one; if the selected direction is continuously wrong for three times, switching the sighting target to a larger sighting target; at this time, the number of times of error switching is increased by one;

when the correct switching and the wrong switching are respectively accumulated for three times, the examinee is judged to reach the eyesight limit at the moment, and the sighting target at the latest correct switching is taken as the current eyesight of the examinee; the invention can detect the object distance D of the examinee in real time and adjust the size of the sighting mark, so that the examinee can not see the sighting mark clearly due to the change of the distance caused by operation behaviors, the accuracy of vision detection is not influenced, the detection method is simple and effective, and the intelligent degree of the vision detection is improved;

as shown in fig. 2, a vision testing method using a general-purpose device with a camera function, applied to a vision testing system, includes:

v1: when the vision detection system is opened on the universal equipment, detecting whether the current universal equipment has a front camera or not through an API (application program interface) of an operating system of the universal equipment;

v2: if the front camera exists, acquiring the focal length information of the current camera through a built-in hardware database, and then inputting the vision record level to be tested through an information input module;

v3: shooting a complete facial picture of a detected person through a front camera, analyzing by combining with the focal length information of the camera, and calculating to obtain the size of a vision detection sighting mark; the method specifically comprises the following steps:

carrying out face detection on a shot complete facial picture of a detected person by using a face detector, and identifying the outline of five sense organs, particularly the positions of pupils of two eyes;

acquiring the interpupillary distance width W of a detected person according to the positions of pupils of two eyes; marking the focal length of the camera as F, and marking the picture pixel width of the camera as P; the object distance D of the current distance lens of the person can be calculated according to a similar triangle method, and the specific calculation mode is as follows: d ═ W × F)/P;

acquiring vision record levels to be tested, wherein each vision record level has a corresponding visual target constant; then the calculation formula of the side length E of the detected sighting target is as follows: e ═ optotype constant × 250 × α × p; wherein alpha is the angle between two points on the visual target at the eye node N, and p is the width of the picture pixel of the camera; alpha corresponds to the object distance D of the person from the lens;

v4: displaying the corresponding size of the sighting target on a display screen of the universal equipment according to the side length E of the detected sighting target, and selecting the direction of the sighting target viewed through a direction key on the display screen after the examinee detects one line of sighting target; analyzing according to the visual target direction selected by the examinee to determine the current vision of the examinee, and the specific analysis steps are as follows:

if the direction is selected to be correct three times continuously, the visual target is switched to a smaller visual target, and the correct switching times are increased by one; if the selected direction is continuously wrong for three times, switching the sighting target to a larger sighting target; at this time, the number of times of error switching is increased by one;

and when the correct switching and the wrong switching are respectively accumulated for three times, judging that the examinee reaches the eyesight limit at the moment, and taking the sighting target at the latest correct switching as the current eyesight of the examinee.

The invention innovatively calculates the vision detection distance in real time through the computer image technology and calculates the size of the sighting target in real time according to the detection distance, avoids the defect that the detection distance needs to be accurately calculated manually in the traditional vision detection, selects the proper sighting target, simultaneously improves the intellectualization degree of the vision detection, can finish the operation only by the person to be detected, saves the labor, improves the efficiency, can carry out the detection through a network, does not need to be carried out on site in a medical institution, saves the medical resource and improves the social benefit.

The above formulas are all calculated by removing dimensions and taking numerical values thereof, the formula is a formula which is obtained by acquiring a large amount of data and performing software simulation to obtain the closest real situation, and the preset parameters and the preset threshold value in the formula are set by the technical personnel in the field according to the actual situation or obtained by simulating a large amount of data.

The working principle of the invention is as follows:

when the vision detection system is opened on the general equipment, whether the current general equipment has a front camera or not is detected through an AP I of an operating system of the general equipment; if the front camera exists, acquiring the focal length information of the current camera through a built-in hardware database, and then inputting the vision record level to be tested through an information input module; shooting a complete facial picture of a detected person by a front camera, identifying the outline of five sense organs, particularly the positions of pupils of two eyes, acquiring the pupil distance width W of the detected person, calculating the object distance D of the person from a lens at present according to the pupil distance width W, the focal length F of the camera and the picture pixel width P and a similar triangle method, and then calculating the size of a corresponding vision detection sighting mark in real time according to the vision recording level to be tested;

the visual target display module displays visual targets with corresponding sizes on a display screen of the general equipment according to the side length E of the detected visual targets, after a line of visual targets are detected by a detected person, the direction of the visual targets is selected through a direction key on the display screen, if the direction is selected to be continuous and correct for three times, the visual targets are switched to smaller visual targets, and if the direction is selected to be continuous and wrong for three times, the visual targets are switched to larger visual targets; when the correct switching and the wrong switching are respectively accumulated for three times, the examinee is judged to reach the eyesight limit at the moment, and the sighting target at the latest correct switching is taken as the current eyesight of the examinee; the invention can detect the object distance D of the examinee in real time and adjust the size of the sighting mark, so that the examinee can not see the sighting mark clearly due to the change of the distance caused by operation behavior, the accuracy of vision detection is not influenced, the detection method is simple and effective, and the intelligent degree of the vision detection is improved.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims (8)

1. A vision detection system using universal equipment with a camera shooting function is characterized by comprising an image acquisition module, an image analysis module, a visual target display module and a visual target analysis module;

the image acquisition module is used for shooting a complete facial picture of a detected person through the front camera and sending the shot complete facial picture of the detected person to the image analysis module;

the image analysis module is used for receiving a complete facial picture of a detected person, analyzing the complete facial picture by combining with the focal length information of the camera, calculating the object distance D between the person and the lens at present, and then calculating the size of a corresponding vision detection sighting mark in real time according to the vision recording level to be tested;

the visual target display module is used for displaying visual targets with corresponding sizes on a display screen of the universal equipment according to the sizes of the visual detection visual targets obtained by the image analysis module;

the visual target analysis module is used for analyzing according to the visual target direction selected by the examinee to determine the current vision of the examinee.

2. A vision testing system using a general-purpose device with camera function as claimed in claim 1, wherein said image analysis module comprises the following specific analysis steps:

s1: carrying out face detection on a received complete facial picture of a detected person by using a face detector, identifying the outline of five sense organs, intercepting a corresponding face area, and determining the positions of pupils of two eyes;

s2: acquiring the interpupillary distance width of a detected person according to the positions of pupils of two eyes;

s3: acquiring the focal length information of the camera as F, and calculating the object distance of the current distance lens of the person according to a similar triangle method, wherein the specific calculation mode is as follows: d ═ W × F)/P, where: d is the object distance between the person and the lens, W is the pupil distance width of the person to be examined, and P is the picture pixel width of the camera;

s4: calculating the size of a corresponding vision detection sighting mark in real time according to the vision recording level to be tested, wherein the specific calculation method comprises the following steps:

marking an angle formed by two points on the sighting target at the eye node N as alpha, wherein the alpha corresponds to the object distance D between a person and the lens; the side length E of the sighting target is calculated according to the following formula: e ═ optotype constant × 250 × α × p; the visual target constant corresponds to the vision record level to be tested, and each vision record level has a corresponding visual target constant; p is the constant radian coefficient.

3. A vision testing system using a general-purpose device with camera function as claimed in claim 1, wherein said visual target analysis module comprises the following specific analysis steps:

after the examinee detects a line of sighting marks, the direction of the sighting marks which are seen is selected through a direction key displayed on the display screen; judging whether the selection direction is correct or not;

if the direction is selected to be correct three times continuously, the visual target is switched to a smaller visual target, and the correct switching times are increased by one; if the selected direction is continuously wrong for three times, switching the sighting target to a larger sighting target; at this time, the number of times of error switching is increased by one; and when the correct switching and the wrong switching are respectively accumulated for three times, judging that the examinee reaches the eyesight limit at the moment, and taking the sighting target at the latest correct switching as the current eyesight of the examinee.

4. The vision testing system using the universal device with camera function as claimed in claim 1, further comprising a front-end determining module, when the vision testing system is opened on the universal device, the front-end determining module is connected to AP I of the operating system of the universal device, for detecting whether the universal device has a front-end camera or not; if the front camera is arranged, the vision detection system can be normally used on the current general equipment, otherwise, the vision detection system cannot be used.

5. The vision testing system using a general-purpose device with camera function as claimed in claim 1, further comprising an information acquisition module for acquiring the camera focal length information of the current general-purpose device from a built-in hardware database and transmitting it to the image analysis module.

6. The vision testing system using a general-purpose device with camera function as claimed in claim 1, further comprising an information input module for inputting vision recording level to be tested by the examinee and uploading the same to the image analysis module.

7. A vision detection method using a universal device with a camera shooting function is applied to a vision detection system and is characterized by comprising the following steps:

v1: when the vision detection system is opened on the universal equipment, detecting whether the current universal equipment has a front camera or not through an API (application program interface) of an operating system of the universal equipment;

v2: if the front camera exists, acquiring the focal length information of the current camera through a built-in hardware database, and then inputting the vision record level to be tested through an information input module;

v3: shooting a complete facial picture of a detected person through a front camera, analyzing by combining focal length information of the camera, calculating the object distance D between a person and a lens at present, and then calculating the size of a corresponding vision detection sighting mark in real time according to a vision recording level to be tested; wherein, the detection of the size of the sighting target comprises the detection of the side length E of the sighting target;

v4: displaying the corresponding size of the sighting target on a display screen of the universal equipment according to the side length E of the detected sighting target, and selecting the direction of the sighting target viewed through a direction key on the display screen after the examinee detects one line of sighting target; and analyzing according to the visual target direction selected by the examinee to determine the current vision of the examinee.

8. The vision testing method using the universal device with the camera shooting function as claimed in claim 7, characterized in that the current vision of the examinee is determined by analyzing according to the selected sighting target direction of the examinee, and the specific analyzing steps are as follows:

if the direction is selected to be correct three times continuously, the visual target is switched to a smaller visual target, and the correct switching times are increased by one; if the selected direction is continuously wrong for three times, switching the sighting target to a larger sighting target; at this time, the number of times of error switching is increased by one;

and when the correct switching and the wrong switching are respectively accumulated for three times, judging that the examinee reaches the eyesight limit at the moment, and taking the sighting target at the latest correct switching as the current eyesight of the examinee.

Images